In 2013, Marvel Studios released Thor: The Dark World, the eighth film in what was, at the time, a still-experimental attempt to build a unified cinematic universe. The film made nearly $650 million at the global box office, was a technical success by virtually any Hollywood standard, and yet—if you ask the average Marvel fan today to recall its plot, you’ll likely be met with a long pause, followed by something like, “Was that the one with the elves?”